Dental impression material



' absolutely free from any poisonous or injurious Patented Dec. 1, 1942 PATENT OFFICE 7 256mm nmanmnassron Constant A. Benoit and Herman G. Fuchs, Brook'- lyn, N. Y., assignors to Permatex Company, Inc., Brooklyn, N. 1., a corporation or New York NfoDrawing. Application December 26, 1940, Serial No. 371,772

IGQiaims. (cue-41) I As dental impression materials must necessarily be applied within themouth and brought into intimate contact with its delicate tissues, they must possess specific properties and char-' acteristics in order that-theymay'successi'ully 5 meet the peculiar conditions incident to their use. ,From among the evident properties which should he possessed by a composition of matter. adapted for the production of dental impressions, we mention the following: it should be ready for use or easily prepared for use as time is an important factor to the dentist it should be of such physical condition that it can be readily inserted into the fissures and crevices of the soft and hard tissues of the mouth and readily removed therefrom without destruction of the impressions thereof; it should be or such chemical and physical condition as to allow or the production of accurate impressions without the use of heat; it should not require either heating or chilling in the mouth in order to accomplish its successful removal therefrom; it should be of such composition as to, require a minimum 01 time for its application and removal; it should not break up, crumble, or separate in the mouth" thus' removing allpossibility of its entering the throat; it should not generate heat through chemical reaction immediately before or during its application thus keeping the patientat ease and insuring a true impression under normal temperature conditions; it should be of such censtruction as'to give sharp and accurate impressions; it should be of such composition-as to be adapted for pse in edentulous mouthsaswell as in those in which teeth are present; it should 35 be oi. such composition that it will not cause the patient to gag: it should not expand or contract after the impression has been made; it should bereadily removable from the model; it should not stick to the mouth surfaces; it should not be objectionable in taste or odorz. it should be absolutely free i'rom any deleterious or objectionable eilfect upon the mouth tissues; and it should be materials. Y

The above-mentioned are only some of the characteristics which should be possessed by dental impression materials, but they are suiiicientto indicate the care that must be taken in many requirements that must be met in thev able features.

Among the objectionable components 01' previously described compositions suggested for use in the production of dental impressions is plaster of Paris, which generates heat during setting, is

removed with difllculty; has a decided tendency to crack, flake, and break in the mouth and to drop into the throat of the patient; starts contr-acting a few hours after the impression has been made, and'its use in general is objectione able to the patient.

Among' other objectionable ingredients are those chemicals, such as gums and resins, requiring the use of objectionable solvents of an aro- I matic nature, turpentine, or methyl alcohol, all

of which have an irritating eflect upon the mouth tissues, and many of which are injurious if accidentally swallowed.

loids require long experience and very skillful manipulationbefore they can be used with a fair degree of confidence.

Waxes, which have been suggested for impressemi-melted condition in the patient's mouth.

The composition of material of our invention possesses all of the above-mentioned, and other, desirable chemical and physical attributes and none of the objectionable properties described, the preparation of such compositions and the and presents dental impression materials poasfl and thereafter for further operations.

. mation of the impression mass.

, patible ing valuable attributes of the his est practical value It is desirable that a dental impression material should contain a liquid of some kind'in order to produce a composition ,of plastic properties for allowing the production of impressions and that the liquid should be readily and rapidly evaporable in order that its retention in the mouth may require a minimum of time in order not to unduly inconvenience the patient.

It is evident that the moisture content should be as nearly uniform as possible throughout the mass during-and after the formation of the impression in order that the impression may be obtained and retained without undue distortion,

evaporable properties. I

A further necessary property of such aliquid I is that it should be a solvent for those elements of the composition which act as binders for the,

insoluble elements, in order that the binding properties are uniform throughoutqthe mass, thus forming a uniform composition of matter during its application for the production of impressions The most important properties of a solvent adaptable for dental impression materials are tating that ethyl alcohol. Aromatic oils are extremely irritating and have a deleterious eifect upon the mouth tissues.

It is evident from the foregoing description of the requirements necessary in a proper dental impression material that considerable research was necessary in order. to determine the other ingredients which will co-act with ethyl alcohol to produce the desired effect.

. a We. have found that a composition of matter having the described valuable and necessary properties can be obtained.by a composition of matter formed from ethyl alcohol, castor oil,-

Pontianak gum, and Philippine gum.-

Amongthe accelerators (or.'thickeners) ,in-

' cluded in our invention are calcium chloride, zinc chloride, magnesium chloride, calcium nitrate, zinc nitrate, magnesium nitrate, calcium aluminate, calcium oxide, zinc oxide, and magnesium that it must be non poisonous, non-toxic, and

' pression period. Any irritating effect is liable to cause the patient to contract, expand, or otherwise change the position of the mouth contour, thus disturbing and destroying the proper for- It is evident that compositions of matter adapted for-dental impression materials must contain some compound or' compounds, or fillers, which are capable of setting into a mass of sufiicient hardness as to allow of the necessary oxide, but we do not limit ourselves to these specific accelerators.

Among the mineral, vegetable, and animal fillers suitable for use in our composition of matter are talc, China .clay, asbestos, mica, ochre, iron oxide, silica, infusorial earth, diatomaceous earth, graphite, magnesium silicate,

operations upon the composition after the dental impressions have been made, and that these fillers must be chemically and physically comwith the other ingredients.

These fillers must be of such composition that they will form a uniform, pliable, workable mass when inserted within the mouth for the making of impressions; they must not adhere to the mouth tissues; they must not unduly impede the evaporation of the solvent; they must not crumble, crack, or flake while in the mouth or while in molding form: and they must be nonpoisonous, non-toxic, and non-irritating.

It is evident, therefore, that considerable care and research are necessary in order to determine and formulate a proper composition of matter adapted for the production of dental impressions.

- as We have found that ethyl alcohol is particualuminum silicate, calcium carbonate, wood flour, cotton-linters', ground cork, ground wool, and silk fibre, but wedo not limit ourselves to 'these specifically mentioned flllers.

We give the following formulae as examples of compositions of matter according to our invention, but we do not-limit ourselves to these specifically mentioned chemicals or proportions as it is evidentthat they may be varied without going beyond the scope of our invention as described and claimed:

Fouruts 1 r Parts Manila gum 40 Ethyl alcohol a 83 .Magne'sium silicate 95 Raw castor oi 16 B zinc' i 9 Raw linseed -oil 5 I Foasmu2 Manila gum 38 Ethyl alcohol- 32 China clay 85 Blown castor oil 20 Magnesium oxide 10 Raw castor on 4 Foams 3 Philippine gum 40 Ethyl 111001101 32 Calcium car n so Acetylated castor oih 15 All of the above-mentioned parts refer to relative weights of the various materials.

While it is not absolutely necessary to mix the accelerator with an oil before adding it to the mixtures A, we prefer to do so as it allows of a more complete and uniform incorporation of it into mixtures A."

While the mentioned oils are suitable for ourpurposes, we prefer to employ blown castor oil as it produces a more readily applicable material than the others.

In the application of our materials for making dental impressions, we prefer to retain mixtures A and B separate from each other and to mix theni together with thorough stirring for one or two minutes before app ing them.

The above-described dental impression materials of our invention are non-poisonous, nontoxic, practically non-irritating, and tasteless; they will not crack, crumble, or flake during the operations to which they are submitted; they Part8 matter as specifically applicable for the forma- B tion of dental impressions, we do not limit ourcalcium oxide 4 selves to their application for this particular purcalcium alumina, 4 pose, as their composition and physical and Raw linseed on 5 5 chemical properties makes them useful and valu- 4 1 able for all purposeswhere their properties are,

FORMULA 4 such as to successfully meet such required con-' A dllllOl'lS. v

Where we employ the word -oil," the word Phmppme I 39 accelerator, the word gum," and the word Ethyl 30 filler in our claims, we include both .a single .Magnesmm silicate 93 member of each said group and a mixture of a Raw castor on -r 14 plurality of members of each said group.

1 3 We do not limit ourselves to the chemicals and zm ma 8 l5 quantities thereof as speciflcallyset forth in our 0 o 1 v I 4 specification as these are given solely for the Raw m "f "f' I purpose of clearly describing our invention, and Forum-A5 they, may be'varied without going beyond the scope of our invention.

- I v What we claim is: -Pontianak gum 38 1. A composition of. matter adapted for the Ethyl alrnhn'l 32. production of dental impressions comprising eth- China clay 86- yl alcohol, at least one member selected from Blown castor oil 18 the group consisting of castor oil, blown castor B oil, polymerized castor oil, oxidized castor oil,

sulphonated castor oil, esterifled castor oil, by-

Magnesium Oxid? drogenated castor oil and acetylated castor oil;

w linseed 0 5 an ethyl alcohol soluble gum, at least one accel- FORMULA 5 erator for said gum and at leastone filler.

. 0 2. A composition of matter adapted for the A production of dental impressions comprising eth- Pontianak g 4 yl alcohol, blown castor oil, at least one ethyl al Ethyl alcohol 33 001101 s luble gum, at least one accelerator for Calcium carbonate 82 S d um and at least one filler.

Acetylated castor oilr 14 p s ti n of matter adapted for the production of dental impressions comprising th- B yl alcohol, blown castor oil, Manila gum, at least calcium 1 4 one accelerator for said gum and at least one Calcium aluminate 4 filler. I Raw castor oil 4 40 A composition Of matter adapted for the production of dental impressions comprising ethyl alcohol, blown castor oil, Manila gum, mag? nesium oxide and at least one filler.

5. A composition of matter adapted for the production of dental impressions comprising ethyl alcohol, blown castor oil, Manila gum, magnesium oxide and magnesium silicate. I

6. A composition of matter adapted for the. production of dental impressions comprising ethyl alcohol, blown castor oil, Manila gum, magnesium oxide, magnesium silicate and asbestos,

'7. A composition of matter adapted for the production of dental impressions comprising ethyl alcohol, castor'oil, at least one ethyl alcohol soluble gum, at least one accelerator for said gum and at least one filler.

8. A composition of matter adapted for the production of dental impressions comprising ethyl alcohol, castor oil, Philippine gum, and at least one accelerator for said gum and at least are readily workable in the mouth, producing clean, clear, and exact impressions at comfortable temperatures to the patient; they set rapidly in the mouth, from which they are easily and readily removed; they do not gag the patient;

they are easily removed from themold; and they possess the further valuable property that they do not contract or expand during the performance of all necessary operations, thus insuring that the casts produced therefrom coincide in every particular with" the original mouth impressions.

While we have described our compositions of one filler.

9. A composition of matter adapted for. the production of dental impressions comprising ethyl alcohol, castor oil, Philippine gum, zinc oxide and at least one filler.

10. A composition 'of matter adapted for the production of dental impressions comprising ethyl alcohol, castor oil, Philippine gum, zinc oxide and China clay.

11. A composition of matter adapted for the production of dental impressions comprising ethyl alcohol, castor oil, Philippine gum, zinc oxide,

China clay and silk fibre.

12. A composition of matter adapted for the i production or dental impressions comprising et yl alcohol, polymerized castor oil, at least one ethyl alcohol soluble gum, at least one accelerator for said gum and at least one filler.

13. A composition of matter adapted for the production or dental impressions comprising ethyl alcohol, polymerized castor oil, Pontianak gum, at least one accelerator for said gum and at least one filler.

14. A composition of matter adapted for the production or dental impressions comprising ethyl alcohol, polymerized castor oil, Pontianak gum, calcium oxide andat least one filler.

15. A composition oi matter adapted for the production 01' dental impressions 'comprising ethyl alcohol. p lymerized caator oil, Pontianak gum, calcium oxide and silica.

16. A composition of matter adapted for the production 01' dental impressions comprising ethyl alcohol, polymerized eastor oil, Pontlanak sum, calcium oxide, silica and cotton linters.

CONSTANT A. BENOIT. HERMAN C. FUCHS. 

